sather



Feb. 28. 1956 o. H. SATHER 2,736,259

PREMAKE READY PLATE CYLINDER Filed Feb. 5, 1952 6 Sheets-Sheet 1 IN V ENTOR.

B ,a zg gg Feb. 28, 1956 sATHER 2,736,259

PREMAKE READY PLATE CYLINDER Filed Feb. 5, 1952 6 Sheets-Sheet 2 Feb.28, 1956 o. H. SATHER 2,736,259

PREMAKE READY PLATE CYLINDER Filed Feb. 5, 1952 s Sheets-Sheet 5INVENTOR. CYLU/fi 5afkef, BY

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Feb. 28, 1956 o. H. SATHER 3 PREMAKE READY PLATE CYLINDER Filed Feb. 5,1952 e Sheets-Sheet 6 IN V EN TOR.

United States Patent '0 PREMAKE READY PLATE CYLINDER Oliver H. Sather,Chicago, Ill. 7 Application February 5, 1952, Serial No. 269,946

15 Claims. (Cl. 101378) The invention relates to the art of printing andhas reference more particularly to a novel and improved pre-make readyplate' cylinder.

For attaching printing plates to the peripheral surface of rotaryprinting cylinders it has been customary to perforate the surface of thecylinder with a plurality of small openings or grooves, and fasteningmeans have been employed having location in said openings or grooves forreleasably locking printing plates in registered position on thecylinder. It is also old and well known in the art to equip rotaryprinting cylinders with leading and trailing edge clamping meansoperative to clamp stereotype printing plates to said rotary cylinders.The present invention aims to improve apparatus of this nature andaccordingly provides a pre-make ready plate cylinder incorporating"novel and improved clamping means for releasably attaching to thecylinder either a plate carrying jacket or a plate carrying shell. Itmay also be possible to use the improved clamping means of the inventionfor releasably attaching a stereotype plate to rotary printingcylinders.

In order to provide a pre-make ready plate cylinder in accordance withthe inventionthe cylinderjacket or cylinder shell is perforated on itsexterior surface by aplurality of relatively small openings,preferably'disposed in spaced substantially checkerboard arrangement.The printing plates, carrying the matter to be printed, are secured inaccurate register to the peripheral surface of the jacket or shell bythe use of conventional plate hooks and the jacket or shell, which isnowready for printing, is then clamped to the cylinder'in registeredposition thereon by novel clamping means as herein disclosed anddescribed. As a result of the above procedure anumber of specialadvantages are secured. In the first place, the printing plates can beattached in register to the shell in the composing room. Accordingly,the entire operation, which is known as make-ready, can be performedaway from the press and while the press is producing and running offanother job of printing. It is also possible to check the arrangementand disposition of the printing plates'on the shell by a proofingoperation in the composing room before the plate carrying shell isapplied to the press. Another advantage resides in the fact that theoperation of clamping the plate carrying shell to the cylinder can beeffected with speed'and accuracy" so that the period of idleness for theprinting press is imthermore reduced. Y

Therefore another object of the invention resides in the provision ofimproved clamping meansadapted for incorporation within a rotaryprinting cylinder for locking a plate carrying shell to the cylinder,and which clamping means will include two clamping devices, each havinglocation within the cylinder on the respective sides thereof.

Another object of the invention resides in the provision of improvedclamping means adapted 'for incorporation within a rotary printingcylinder as herein described, and wherein the actuating means for eachclamping device will project exteriorly of the cylinder, being locatedat and being accessible to the operator at the conventional gap of thecylinder.

Another object of the invention is to provide improved clamping means asdescribed which will incorporate registering means in the form of afixed registering bar carried by the cylinder and whereby said fixedregistering bar serves to always locate a plate carrying shell on thecylinder. in the same position for accurate registra tion.

A further object is to provide efficient and accurate clamping means forincorporation within a printing cyl inder whereby a plate carrying shellcan be r'eleasably locked in registered position on the cylinder andwhich said clamping means will engage both the leading and trailing edgeof the shell to thereby apply circumferential tension holding the shellto the cylinder.

A more specific object is to provide a novel and improved clamping meansof the character described which will incorporate registering bars withwhich the leading and trailing edge of the shell will contact, andwherein the registering bar for the trailing edge will be located in thecylinder gap and will have openings through which extend the actuatingmeans for the clamping devices.

With these and various other objects in view, the invention may consistof certain novel features of construction and operation as will be morefully described and particularly pointed out in the specification,drawings and claims appended hereto. i in the drawings which illustratean embodiment of the invention, and wherein like reference charactersare used to designate like parts- Figure l is a perspective view of aplate carrying shell constructed in accordance with the invention, thesame being illustrated with several printing plates releasably securedthereto;

Figure 2 is an enlarged fragmentary plan view of a section of the shellillustrating the arrangement of the openings;

Figure 3 is a sectional view taken along line 3-3 of Figure 2;

Figure 4 is a transverse sectional view of a pre-make ready printingcylinder illustrating a preferred form of clamping means for the platecarrying shell;

Figure 5 is a transverse sectional view similar to Figure 4 but showingcertain clamping members in released position;

Figure 6 is an elevational view of the gap side of the pre-make readyprinting cylinder of Figures 4 and 5, illustrating the location andarrangement of the clamping means and the actuating means at this sideof the cylinder;

Figure 7 is a transverse sectional view of a pre-make ready printingcylinder illustrating a modified form of clamping means for the platecarrying shell;

Figure 8 is a fragmentary transverse sectional view illustrating themodified clamping means of Figure 7 but showing only the clampingstructure for engaging the plate carrying shell at the gap side of thecylinder; and

Figure 9 is a transverse sectional view of a pre-make ready printingcylinder illustrating a further modification of shell and clamping meanscoming within the invention;

Figure 10 is a front elevational view of the clamping member 97 keyed toshaft 76 so as to rotate for clamping and releasing its plate carryingshell;

Figure 11 is an elevational view of one of the spring tensioning deviceson shaft 76; and

Figure 12 is an end view with parts being shown in section of a modifiedform of the invention wherein the cylinder is provided with a singleplate carrying shell.

In the drawings, the base portion of the printing cylinder isillustrated as having at least one and'may have as many as four platecarrying shells attached thereto by clamping members at the leading edgeand at the trailing edge of each shell. Such a plate carrying shell maytake the form as shown in Figure 1, wherein the shell identified bynumeral is semi-circular in transverse section, having the longitudinalgrooves 11 and 12 formed on the interior surface at the leading andtrailing edges, respectively, for coaction with clamping members, theconstruction and operation of which will be presently described. Theprinting plates such as 13 and 14 are releasably secured to the exteriorsurface of the shell by plate hooks 15 which are located in openings 16.Said openings are arranged in honeycomb formation on the exteriorsurface of the shell Figure 2 in order that the plates may be securedthereto in the desired adjusted positions. The bottom of each opening 16is reduced in diameter by section 17 Figure 3, which thereby forms theshoulder 18 with which the plate hooks engage and by which said meansare locked in the openings.

Figure 4 illustrates a printing cylinder having top and bottom platecarrying shells clamped thereto by improved clamping means coming withinthe invention. The base portion of the cylinder is identified by numeral22, and is provided with a number of cored openings 23 and 24 forreducing the weight of the cylinder, and which openings extendlongitudinally of the same. At diametrically opposite sides of the baseportion the same is provided with longitudinal grooves or recesses foraccommodating the clamping members which serve to clamp the shells tothe base portion in a manner to lock them in registered position on thecylinder. The groove 25 of keystone shape, having the undercut edges 26,extends from end to end for the length of the cylinder and said groovereceives the registering bar 27 of equal length and which is securedcentrally of the groove by the securing screws 28. The top and bottomsurfaces of the registering bar have a slight taper in an outwarddirection. A taper of about one degree is preferred. The clampingmembers 30 and 31 contact with and ride on the said tapering surfaces,identified by numeral 29. For clamping purposes each member is providedwith a nose 32 adapted to enter and coact with its particular groove 11in the leading edge of a plate carrying shell. Each clamping member hasa tapering formation in cross section since the outer surface of eachmember is formed to engage its respective undercut surface 26.

Actuating screws comprise the means for actuating the clamping membersto effect radial movement thereof into and out of clamping relation withthe grooves 11 in the shell. Clamping member 30 is actuated by screw 33which extends through passages in the base portion provided therefor andprojects into the longitudinal groove 35 similar to groove 25 but beingrectangular in shape and being located at the gap side of the printingcylinder. The actuating screws 33 and 34 are threaded at their left handend as at 36 for threaded engagement with their respectlve clampingmember. At their opposite end each actuating screw is provided with ahead portion 37 having location in recess 38 provided therefor and theterminal end of each screw is squared as at 40 for receiving a tool orthe like by which the actuating screw is turned by the operator. Thebottom of groove 35 receives the thrust plate 41 which is suitablyfastened in place by the securing screws 42. The thrust plate acts as acover for recesses 38 and as a stop for the heads 37. When the actuatingscrews are rotated to produce outward movement of the clamping members30 and 31 to effect a loclrin g'of the plate carrying shell, the thrustresulting from this operation is absorbed by plate 41, being impartedthereto by the heads 37. When the clamping members are moved in anopposite direction, that is, inwardly of the printing cylinder for thepurpose of releasing the plate carrying shells, the heads 37 move intocontact with the bottom of the recesses 38 and the thrust of thisoperation is thus transmitted to the cylinder.

The p g ars 43 and 44 are prov ded f r ping the opposite edge of theplate carrying shells at the gap side of the printing cylinder. The barsextend for approximately the length of the clamping members, ha inglocation within the longitudinal groove 35 and being retained in thegroove by retaining plates 45. Said plates are located at spacedintervals for the length of the clamping bar and each bar is providedwith an opening such as 46 through which the extending end of theretaining plate 45 projects. The securing screws 42, which fasten thethrust plate 41 to the base portion of the cylinder, can be employed foradditionally bolting the retaining plates 45 which lie flat against theouter surface of the thrust plate, all as clearly shown in Figure 6.When the clamping bars 43 and 44 are not in use they are still retainedwithin the longitudinal groove 35, being allowed to drop down to thebottom of the groove, which has the efiect of removing the taperedclamping end 47 of each bar below the surface of the base portion andtherefore out of coaction with a groove, such as 12, in the platecarrying shell. For accommodating the clamping bars when in operativeclamping relation with the plate carrying shell, the thrust plate 41 isnotched as at 4-8 on respective sides thereof, as will be clear from aninspection of Figure 5. When the clamping bars are located in theirrespective notches the tapered nose 47 thereof will be located within agroove such as 12 in the plate carrying shell on the cylinder.

Numerals 5t) and 51 indicate the actuating screws for the clamping bars,the same having threaded relation with a bar and being adapted to engagea side wall of the longitudinal groove 35. The head of each actuatingscrew 50 and 51 is squared as at 52 for receiving a tool or the like bywhich the actuating screw is turned and when the same is turned in acertain direction its actuating bar is caused to coact with the groove12 of the shell, applying circumferential tension thereto, thus lockingthe shell to the cylinder, provided, of course, that the opposite end ofthe shell is held by a clamping member 30 or 31.

The manner of clamping a plate carrying shell to the cylinder isillustrated in Figure 5, wherein the shell 21 is shown in clampedposition, whereas, shell 20 has just been placed on the cylinder and isnot as yet clamped thereto. For such purpose the operator employs asuitable tool engaging the squared end 40 of the actuating screw 33, torotate the screw and cause outward movement of the clamping member 30 ina substantially radial direction to locate nose 32 of the member withingroove 11. The next operation results in the proper positioning of theclamping bar 43 in its recess 48 on the thrust plate 41. The actuatingscrew 50 is then rotated in the proper direction to force the clampingbar 43 in a downward direction whereby to apply the necessarycircumferential tension to the shell 20 to securely lock the same inregistered position on the printing cylinder. The one degree taper onthe top and bottom surfaces 32 of the registering bar 27 is such as tofacilitate the sliding movement of the clamping members 30 and 31 on theregistering bar and location of their nose portions 32 into the grooves11 of the plate carrying shells. The surfaces 32 are accurately machinedand the registering bar is accurately positioned centrally within thelongitudinal groove 25 so as to provide a registering means foraccurately positioning the plate carrying shells on the cylinder. Theeffect of the tapering surfaces 26, in combination with the surfaces 32is to limit outward movement of the clamping members. Said members moveoutwardly and stop just short of their nose portions 32 contacting thebase of grooves 11 in the shells. However, each shell will be accuratelypositioned since the clamping edge 53 of each nose portion will beforced into a close sliding fit with the outer edge of groove .11. 7

It will be observed that the clamping members and clamping bars are allactuated from the gap side of the cylinder. ,Accordingly, from this sideof the cylinder the and 21.

the cylinder.

the gap side of the cylinder.

'70, 71 and 72 secure the blockswithin their respective r operator canactuate screws ,33 and 34 forthe clamping members and can also actuatescrews andi51.for' the clamping bars. As a result the clamping of ashell to the cylinder can be effected with great speed and accuracy andeven less time is required to release the members and bars in ordertoremove the clamping shell from the cylinder. As shown in Figure 6, atotal of four plate carrying shells may be releasably. locked to acylinder such as 22, havingendmembers v54 and 55. Plate carrying shells20 and 21 are locked to the cylinder by structure such as described,rtheshells being located at the right hand end of the cylinder in endcontact with member 54. Depending on the length of the cylinder, it maybe possible to apply thereto apair of similar plate carrying shells20aand 21a, the same being located at the left hand end of the cylinder andin contact with shells Clamping means as described will also be employedfor locking shells 20a and 21a to the cylinder. End member 55 isprovided with a plurality of adjusting screws such as 56 and whichscrews extend in a longitudinal direction through the end member so asto con tact the plate carrying shells 20a and 21a. By tightening thescrews 56 end play can be taken up at this end of the cylinder. Asillustrated in Figure 6 it will be seen that each plate carrying shellis held by two clamping members and by two clamping bars, with eachclamping member and bar having at least two actuating screws in.threaded relation therewith.

In Figures 7, 8 and 9 a modified form of clamping means is disclosed,the same being characterized by registering bars with which the shellsare adapted to directly contact for locating the shells in registeredposition on The base portion of the cylinder, indicated by numeral 60,is provided with a plurality of longitudinally extending cored openings61 and 62 for reducing the weight of the cylinder. On diametricallyopposite sides the cylinder is provided with longitudinal grooves ofsubstantially similar shape, although inverted with respect to eachother, as clearly evident from an inspection of Figure 7. Thelongitudinal groove on the left hand side of the cylinder is indicatedby numeral 63, whereas, the longitudinal groove on the right hand sideis indicated by numeral 64. Journalling blocks are located in eachgroove, numerals 65 and 66 indicating the blocks located in groove 63,similar blocks 67 and 68 being located in groove 64 since the clampingstructure of this modification is the same at both sides of thecylinder, with the actuating screws therefor being operable from onlySecuring screws such as longitudinal grooves. For purposes of theinvention each .block 65 and 67 has secured thereto a registering bar.

For example, block 65 has theregistering bar 73 suitably secured theretoby screws 74, as best shown in Figure 9, and in a similar mmner theregistering bar 75 is secured to the block 67. It will be understoodthat registering bar 73 is located at the gap side of the cylinder,whereas, bar 75 is located on the side opposite the gap.

Referring more particularly to block 65, it will be understood that aplurality of these blocks are disposed in end to end relation for thelength of the groove 63, see Figure 9. Said blocks journal an actuatingshaft 76 for the clamping members 77. ,A number of such clamping membersare secured to shaft 76 in spaced relation along the length of theshaft, the members being keyed to the shaft as at 78 and each memberhaving a nose portion 80 adapted for location within a groove such as81, providedon the interior surface adjacent one edge of the platecarrying shell v82. Each block 65 approximately centrally of its lengthis suitably recessed for receiving a spring tensioning device for theshaft 76, the same including an arm 83 securely fixed to a flattenedportion of shaft 76 by the screw 84, see Figure 11. The arm extendsinwardly of said recess and is adapted to overlie the coil spring 85 inopening 86 in jaw member 7 l s m e 9 sh tflfi an sxts d sw said recess.The action of the coil spring, with respect to the jaw member and 'arm,is to tension shaft 76 and take up any play in the parts as'a result ofmanufacture or such as may develop by wear. g i i At spaced locations,alternating with the springtensioning device, the clamping members arekeyed, as described, to the actuating shaft 76. One member for eachshaft 76 is provid ed witha pair ofl'bifuirjc'ated arms 88 within whichislocated the, block 89, the samebeing suitably pivoted to the arms bytrunnionssuch as '90. Each block has threaded connection with artactuating screw 91 which extends to the gap side of the cylinder wherethe same is provided with head 92 suitably socketed for receiving a toolor the like, thus permitting the operator to rotate the actuating screwfor effecting actuation of the clamping member 77. The head! is locatedwithin a recess provided therefor in the registering bar 73, the bottomof the recess being provided by the block 65. Thus, the block 65 orbar73func tions to absorb 'the thrust of the actuating screw 91 when thesame is rotated either to clamp the plate carrying shell orrelease aplate carrying shell. A tool receiving opening. i s formed in theregistering bar 73 in alignment with the socketed opening 92' inactuating screw 91 :inorder to allow for insertion of a tool into saidsocketed opening.

Similar structure is provided, as shown by Figure 7, including a movableclamping member, actuating shaft and screw for the plate carrying, shell9 4. Said shell at one end thereof, on its interior surface, is providedwith the groove 95 for receiving thenose 96 of the movable clampingmember 97. Said clamping member 197 is similar in all respects toclamping member 77, the same being keyed at 78 to an actuating shaft76suitably journalled by the blocks 67, located in the groove at this sideof the cylinder. Spring tensioning devices are provided therefor, seeFigure 11, including the arm 83 suitably secured to shaft 76 by screw 84and which arm is tensioned as described by coil spring 85, havinglocation in the jaw member 87. One clamping member 97 for each shaft 76has bifurcated arms 98, Figure 10, within which is jlocated the block100. Said block has threadedrelation with the actuating'screw 01 whichextends transversely of the cylinder to registering bar,73. ,Actuatingscrew 101 is provided with a head 102 having location within a recessformed in the registering bar 73. Here also the bottom of the recess isprovided by the block 65. The head is socketed'at 102 for receiving atool and'the opening 104 in the registering bar is aligned with thesocketed opening in order to allow the insertion of the tooltherein sothat the operator may rotate actuating screw ml to in turn actuateclamping member 97.

The cylinder 66 is provided with stationary clamping members located onapproximately diametrically opposite sides of the cylinder and whichstationary clamping members are suitably supported by the blocks 66 and68,respectively. Referring firstof all to block 66, it will be seen thatsaid block is held in its longitudinalgroove by its securing screw 72.Certain blocks are spaced longitudinally of the groove asillustratedinFigure 9, and a stationary clamping member 105 is disposed betweencertain spaced blocks, being supported therefrom by the supporting shaft106, suitably journalled by said spaced blocks. Each stationaryclampingmember 105 is provided with a nose portion 105a adapted to entera groove 1115b provided on the interior surface of plate carrying shell94 and which is located at the edge opposite groove 95. The stationaryclamping member 105 maybe suitably keyed or otherwise fastened to shaft106 by pin 99. The member 105 is backed by the coil spring 103 locatedin recess 109. The action of the'coil spring issimilar' to the springtensioning devices p'reviously'described" in that it takes up play inthe'partsf Actually, the clamping member 105 has movement of less thanone-sixteenth'of an inch. The blocks'68'are disposed in a similar mannerin their' respective' grooves on the opposite side of the cylinder andcertain spaced blocks journal the supporting shaft 110'which in turnsupports the stationary gripping member 111. Each gripping member 111 isprovided with a nose 112 adapted to enter a groove such as 113 formedalong this edge on the interior surface of the plate carrying cylinder82. Each member 111 may be secured to its supporting shaft 110 by beingkeyed or pinned as at 114. Here also the cylinder is recessed at 115 forreceiving the coil spring 116 which backs the stationary gripping ingmember 97 is actuated into retracted position by rotation oftheactuating screw 101. The semi-circular shell is then fitted to thecylinder with the groove 198 being located on nose portion 107 of thegripping member 165. Actuating screw 101 is then rotated in an oppositedirection to effect a clamping of the shell on the cylinder by locatingnose 96 of the movable clamping member 97 into the groove 95. For thispurpose a suitable tool is inserted through opening 104 into thesocketed end of head 102, and the actuating screw 101 is convenientlyrotated by the operator. der it will be observed that the edge adjacentgroove 95 is in firm contact with the registering bar 75. In a similarmanner the top shell 82 can be clamped to the cylinder whichnecessitates actuation of the actuating screw 91.

When said shell is in place it will be seen that its longitudinal edgeadjacent groove 81 will be in contact with the registering bar 73.

The modification disclosed in Figure 12 employs a single shell forcovering the peripheral surface of the cylinder with the exception ofthe gap opening in the cylinder. In this modification the gap openingextends for approximately ninety degrees and it is possible by usingsaid gap opening to apply a single plate carrying shell to the cylinder,the shell being removable in a manner substantially the reverse to thatof its application.

The cylinder, generally indicated by numeral 124}, is provided with thegap opening 121, extending for approximately ninety degrees so that theoperative surface of the cylinder comprises the remaining two hundredand seventy degrees. The plate carrying shell 122 is adapted to coverthe operative surface of the cylinder and accordingly extends from oneside of the gap opening around the cylinder to the other side of the gapopening. At each longitudinal edge of the shell the same is providedwith a groove such as 123 and 124, respectively. of the gap opening thebody portion of the cylinder is recessed for receiving clamping bars bymeans of which the shell is securely clamped to the cylinder. The recess125 extends longitudinally of the cylinder for the length of the sameand this recess receives the wear plate 126 suitably bolted to thecylinder by the threaded bolts 127. The wear plate 126 provides theshoulder 128 adapted to locate the clamping bar 130 so that its terminalend is located in groove 123 of the shell. In order to remove theclamping bar 130 from clamping relation with the shell the bar isreleased from contact with shoulder 12.8 and the same is allowed to dropto the base of recess 125 in a direction inwardly of the cylinder. Forthis purpose the slot 129 is provided in the clamping bar 130. The saidslot receives the actuating screw 131 by means of which the clamping baris fixedly secured to the wear plate 126 and thus to the cylinder. Oneor more actuating screws may be provided for the clamping bar 130, thesame being suitably spaced longitudinally of the bar and each beinglocated in a transversely elongated slot 129 With the shell in clampedposition on the cylin- On each side which permits operative andinoperative positioning of the clamping bar. Along the opposite side ofthe gap opening in the cylinder wall a recess 132 is provided similar torecess 125'. However, the clamping bar 133 has location in recess 132,the same having the slot 134 formed therein through which is adapted toextend the retaining plate 135. The clamping bar 133 is renderedoperative for clamping a shell to the cylinder by means of the actuatingscrews 136 having threaded relation with said clamping bar.

To render the clamping bars 130 and 133 operative they are located inthe corner slots provided therefor, which sufliciently elevates theclamping bars so that their opposite end is projected into itsrespective groove, either 123 or 124, in the plate carrying shell. Theclamping bar 130 may be considered as the stationary bar with 133comprising the movable clamping bar. Circumferential tension is appliedto the plate carrying shell by actuation of the screws 136 havingthreaded relation with clamping bar 133. These screws can be turneduntil the shell is tightened and firmly clamped to the cylinder. It willbe observed that the actuating screws terminate in a gap opening of thecylinder and that both groups of actuating screws therefore are operablefrom this side of the cylinder.

in removing the single plate carrying shell 122 from the cylinder it is,of course, first necessary to release clamping bars 126 and 133. Inreleased position the bars are located in the bottom of their respectiverecesses. The shell is now rotated relative to the cylinder to positionone longitudinal edge in the gap opening of the cylinder, and saidrotation is continued until the gap opening permits withdrawal of theshell in a lateral direction from the cylinder. In returning the platecarrying shell to the cylinder 120 the same procedure is repeated withthe steps, however, being reversed.

The invention is not to be limited to or by details of construction ofthe particular embodiment thereof illustrated by the drawings as variousother forms of the device will of course be apparent to those skilled inthe art without departing from the spirit of the invention or the scopeof the claims.

What is claimed is:

l. A printing cylinder assembly comprising a cylinder and separableshells therefor adapted to cover the peripheral surface of the cylinderexcept for the conventional opening at the gap side of the cylinder,each shell being semi-circular in cross-section, and clamping meansengaging each shell adjacent the longitudinal edges respectively, saidclamping means including a movable clamping member mounted for movementby the cylinder, an actuating screw having threaded relation with theclamping member for effecting movement thereof, and a second clampingmember for each shell also having an actuating screw in threadedrelation therewith, the actuating screws for both clamping membersterminating at the gap side of the cylinder and being operable from thisside of the cylinder, the second mentioned clamping member being looselysecured to the cylinder and each of said clamping members being capableof movement relative to the cylinder to a limited extent.

2. A printing cylinder assembly comprising a cylinder and at least twosemi-circular plate carrying shells for said cylinder for covering theperipheral surface of the same except for the conventional gap openingat one side of the cylinder, a pair of clamping members for each shellfor clamping the shell to the cylinder, one of said clamping membersbeing mounted by the cylinder for movement approximately radially of thecylinder, the other clamping member comprising a clamping bar looselysecured to the cylinder at the gap side thereof and being capable ofmovement relative to the cylinder to a limited extent, an actuatingscrew having threaded relation with the first mentioned clamping memberfor effecting radial movement thereof, and a second actuating screwhaving greases threaded relation with the clamping bar, bothsaid'actuating screws terminating in the gap opening-and being operablefrom this side of the cylinder.

3. A printing cylinder assembly comprising a cylinder and at least twosemi-circular plate carrying shells for said cylinder for covering theperipheral surface of the same except for the conventional gap openingat one side of the cylinder, a pair of clamping members for each shellfor clamping the shell to the cylinder, a registering bar fixed to. thecylinder and extending longitudinally of the same, one of said clampingmembers being mounted by said registering bar for transverse movementinto and out of clamping position, the other clamping member comprisinga clamping bar loosely secured to the cylinder at the gap side thereofand being capable of movement relative to the cylinder to a limitedextent, an actuating screw having threaded relation with the firstmentioned clamping member for effecting transverse movement thereof, anda second actuating screw having threaded relation with the clamping bar,both said actuating screws terminating in the gap opening and beingoperable from this side of the cylinder.

4. A pre-make ready plate cylinder, the combination of a cylinderportion and a plate carrying shell therefor, said cylinder portionhaving a pair of longitudinal grooves diametrically spaced on oppositesides of the cylinder, one groove forming the gap opening for thecylinder, the other groove having side walls which are undercut inwardlyof the cylinder, a registering bar fixed to the cylinder and locatedcentrally in the base of the last mentioned groove, clamping means forclamping the shell to the cylinder including a movable clamping memberdisposed on each side of the registering bar in contact therewith, eachclamping member having a tapering outer surface complementary to theslope of its adjacent wall of said groove, whereby outward movement ofeach clamping member is limited, other clamping members disposed in thegroove at the gap side of the cylinder, each said last mentionedclamping member including a longitudinal clamping bar, retaining meansfor each clamping bar, and actuating means individual to each clampingmember and to each clamping bar.

A pre-make ready plate cylinder as defined by claim 4, wherein theactuating means consists of an actuating screw for each clamping memberand for each clamping bar having threaded relation therewith, andwherein said actuating screws terminate in the gap opening and areoperable from this side of the cylinder.

6. A pre-make ready plate cylinder, the combination of a cylinderportion and a plate carrying shell therefor, said cylinder portionhaving a pair of longitudinal grooves diametrically spaced on oppositesides of the cylinder, one groove forming the gap opening for thecylinder, the other groove having side walls which are undercut inwardlyof the cylinder, a registering bar fixed to the cylinder and locatedcentrally in the base of the last mentioned groove, clamping means forclamping the shell to the cylinder including a movable clamping memberdisposed on each side of the registering bar in contact therewith, eachclamping member having a tapering outer surface complementary to theslope of its adjacent wall of said groove, whereby outer movement ofeach clamping member is limited as a result of contact of the taperingouter surface of the member with its respective wall of the groove, andactuating means individual to each clamping member for effectingmovement of the same into and out of clamping relation with said shell,said actuating means extending transversely of the cylinder andterminating in the gap opening of the cylinder.

7. A pro-make ready plate cylinder as defined by claim 6, wherein theside walls of the registering bar, having contact with the clampingmembers respectively, are tapered in a direction outwardly of thecylinder portion to facilitate coaction of the clamping members with ashell 10 on the cylinder to effect a clamping of' the shell or a re-'lease or the shell. 7

8. A pre-make ready plate cylinder, the combination of a cylinderportion adapted to have one or more plate carrying shells clampedthereto, said cylinder portion having a pair of longitudinal groovesdiametrically spaced on opposite sides of the cylinder, one grooveforming the gap opening for the cylinder, the other groove having abottom wall substantially normal to a radius intersecting the bottomwall centrally of its length and having inwardly undercut side walls, aregistering bar fixed to the cylinder and located centrally of thebottom wall of said last mentioned groove, and clamping means carried bythe cylinder portion including a movable clamping member disposed oneach side of the registering bar in contact therewith, each clampingmember having a tapering outer surface complementary to the slope of itsadjacent undercut wall of said groove, whereby outer movement of eachclamping member is limited as a result of contact of the tapering outersurface of the member with its respective side wall of the groove.

9. In a rotary printing press, a plate cylinder having at least onelongitudinal groove in its peripheral surface, a clamping memberdisposed in said groove and adapted to have movement transversely of thecylinder to be projected from or to be retracted within the groove, saidclamping member in cross-section having an outward taper and said groovein crosssection becoming wider inwardly of the cylinder and providingsloping surfaces complementary to those of the clamping member, wherebysaid groove serves to limit the forward projecting movement of theclamping member, and actuating means for said clamping member, saidactuating means extending transversely of the cylinder to the sidethereof diametrically opposite the groove and being operable from thisside of the cylinder.

10. In a rotary printing press, a plate cylinder having at least onelongitudinal groove in its peripheral surface, said groove incross-section being keystone in shape and having a bottom wallsubstantially normal to a radius intersecting the bottom wall centrallyof its length and having sloping undercut side walls, a registering barfixed to the cylinder and located centrally of the bottom wall of saidlast mentioned groove, and clamping means carried by the cylinderincluding a movable clamping member disposed on each side of theregistering bar and adapted to contact the bar, each clamping memberhaving movement transversely of the cylinder to be projected from or tobe retracted Within the groove, each clamping member in cross-sectiontapering in an outward direction and having a sloping outer surfacecomplementary to the slope of its adjacent undercut wall of said groove,whereby movement of each clamping member in an outward direction islimited as a result of contact of the sloping surface of the member withits respective wall of the groove, and actuating means for said clampingmembers respectively, each said actuating means extending trans verselyof the cylinder to the side thereof diametrically opposite the grooveand being operable from this side of the cylinder.

11. A rotary printing press as defined by claim 10, additionallyincluding clamping bars located on the side of the cylinder opposite thegroove, wherein the cylinder on this side is provided with a secondgroove extending longitudinally and within which are located theclamping bars, retaining means for the clamping bars which permitlimited relative movement of the bars with respect to the cylinder, andactuating screws for the bars respectively having threaded relationtherewith.

12. A printing cylinder assembly comprising a cylinder ing plates to theshell, clamping means for releasably securing the plate carrying shellto the cylinder, said clamping means including clamping devices withinthe cylinder on respective sides thereof for engaging the trailing edgeof the shell at the gap side of the cylinder and the leading edge of theshell at the side of the cylinder opposite the gap, actuating means forcertain of said clamping devices, said actuating means extendingtransversely within the cylinder, and said actuating means terminatingat the gap side of the cylinder and being accessible to the operatorthrough the gap at this side of the cylinder.

13. A printing cylinder assembly comprising a cylinder and separableshells therefor adapted to cover the peripheral surface of the cylinderexcept for the conventional opening at the gap side of the cylinder,each shell being adapted to support one or more printing platesreleasably securely thereto, and each shell having a longitudinal groovelocated adjacent each edge on the interior surface thereof, clampingmeans for releasably securing each plate carrying shell to the cylinderincluding clamping devices within the cylinder on respective sidesthereof for engaging the trailing edge of the shell at the gap side ofthe cylinder and the leading edge of the shell at the side of thecylinder opposite the gap, and actuating screws for certain clampingdevices for moving the same into and out of coaction with a groove inits particular shell, each actuating screw having threaded relation withits clamping device and extending transversely within the cylinder toproject exteriorly of the cylinder at the gap side of the same.

14-. A pre-make ready plate cylinder comprising the combination of acylinder portion and a semi-circular plate-carrying shell therefor, saidshell having a groove along each longitudinal edge on the inside surfaceof the shell, said cylinder having clamping members adapted to coactwith the grooves for clamping the shell to the cylinder, certainclamping members being movable and other clamping members beingstationary, said cylinder portion having diametrically spaced recessesextending longitudinally on opposite sides of the cylinder foraccommodating the clamping members respectively, supporting meansdisposed in one recess and extending longitudinally for the lengththereof, a shaft journalled for rotation in said supporting means, saidmovable clamping members being keyed to the shaft and being disposed atintervals along the length of the shaft, at least one actuating screwhaving threaded relation with a movable clamping member for actuatingthe same upon rotation of the screw, whereby said shaft is rotated tothus actuate the other clamping members keyed to the shaft, saidactuating screw extending transversely within the cylinder and beingjournalled thereby, and said actuating screw terminating on that side ofthe cylinder having said other recess and relatively adjacent said otherrecess, and other supporting means having location in the other recessand being disposed longitudinally of the cylinder, the said stationaryclamping members being supported by the said other supporting means.

15. A pre-make ready plate cylinder, comprising the combination of acylinder portion and plate carrying shells therefor, said cylinderportion having a pair of longitudinal recesses formed therein at the gapside of the cylinder and at the side diametrically opposite the gap,respectively, supporting means disposed in one recess of each pair, eachsaid supporting means extending longitudinally of its recess andproviding a registering bar, a shaft journalled in each of saidsupporting means, at least one clamping member keyed to each shaft andthus being movable upon rotation of the shaft, a stationary clampingmember disposed in the other recess of each pair and being fixedlysecured to the cylinder, said plate carrying shells each having a groovealong its longitudinal edges and with which the clamping members atrespective sides of the cylinder are adapted to engage for clamping theshells to the cylinder portion with the leading edge of each shell incontact with its respective registering bar, and an actuating screw forrotating each shaft to thus actuate the movable clamping members keyedto the shafts, said actuating screws extending transversely within thecylinder and being journalled thereby, and said actuating screwsterminating at the gap side of the cylinder and having their terminalends in associated relation with the registering bar at this side of thecylinder.

References Cited in the file of this patent UNITED STATES PATENTS433,232 Brooks July 29, 1890 852,786 Hodgman May 7, 1907 2,047,357Crafts July 14, 1936 2,050,950 Huck Aug. 11, 1936 2,496,200 Crafts Jan.31, 1950

